Lessons learned in both the global war on terror and in the Haitian humanitarian missions in 2010 dictate the need for additional radio communications capabilities on aircraft and other military equipment. In Haiti, United States Navy aircraft were the first on the scene to identify critically damaged areas, accumulations of victim populations, landing areas, and land routes to reach victims. A similar mission was undertaken following the unfortunate earthquake and tsunami in Japan in 2011. Flexibility of aircraft and other military communication systems is vital for effective performance of these types of missions.
However, current radio communications are no longer capable of meeting worst-case humanitarian and/or hostile environment coordination activities. In humanitarian missions, improvements are needed to ensure the speed and accuracy of distributing help to victims. In hostile environment missions, improvements are required to ensure the safety of ground personnel and prevent unplanned events such as fratricide, wrong target hits, civilian casualties, etc., while at the same time conducting planned mission operations. Unfortunately, humanitarian needs and hostile opposition can also happen simultaneously thereby presenting additional challenges for military forces. These challenges would be best met through improvements and increases in aircraft communications capabilities which would require an upgrade to existing radios and radio frequency (RF) distribution systems.
Transceivers that have been in use until the current time have mostly been single band and/or single mode radios. That is, radios operated in only one band, which is only one frequency range, such as 225 to 400 MHz, or 30 to 88 MHz. Radios also operated in only one mode such as in Line of Sight (LOS) mode, or in Satellite (SATCOM) Mode. In this connection, radio frequency distribution (RFD) refers to the means by which radios are connected to their respective antennas so that each radio can transmit and/or receive signals. The RFD for the old generation of single band/single mode radios was referred to as “stove pipe”, wherein each radio had its own “vertical stack” (or stove pipe) of connecting cables and other related RF components such as high power amplifiers and tunable bandpass filters up to and including the antennas. Stove piping is a physical constraint in the controls that may be used for the RFD components. For example, the standard UHF shipboard multicoupler used fleetwide by the US Navy and many other navies around the world includes its own control head built into the top front face of the multicoupler. Use of modern multi-mode, multi-band communications requires a departure from the legacy stove pipe approach.
Radio manufacturers have made significant improvements to combine the operations of different bands and modes into single radio units, which units are referred to herein as multi-mode, multi-band (M3B) transceivers. Presently, the ultimate M3B transceiver design achievement is a US Department of Defense (DoD) program known as the Joint Tactical Radio System (JTRS). The original goal for the JTRS program was to reduce procurement and logistics costs by avoiding the practice of each branch of military service (e.g., Army, Navy and Air Force) buying its own distinct radios even though each service shared the same battlespaces and frequency spectra. Another JTRS goal was to have one radio that was software reconfigurable so that the one radio can be used in different bands and modes. These goals have been achieved via the currently produced and fielded M3B radios and via the emerging JTRS-compliant radios. However, still unachieved is full implementation of these radio systems into aircraft, ship and ground communications systems as well as full exploitation of the these new radios in order to realize another of their benefits, namely, multi-mode, multi-band use of each radio on a ship or aircraft or ground system to the maximum extent possible. As will be described in greater detail hereinafter, this goal is most efficiently and effectively achieved, according to the present invention, via a reconfigurable RF distribution that quickly and easily provides the capability to reconfigure the entire radio system for different combinations of bands and modes.
For example, an aircraft mission might begin with a suite of aircraft radios distributed for a certain combination of satellite, air-to-air, and air-to-ground communications. However, during the mission, an emergency may arise in which additional communications links are required between the aircraft and ground forces. In the current state of the art, reconfiguration of radios to different bands and modes is not straightforward, easy or fast. Often the operators are left to transfer radio and RFD operations to different bands and modes via banks of toggle switches. Care must be taken to avoid operator error which can permanently damage radio communications and cause premature termination of the mission. Even if transfer of radios and RFD paths is accomplished via a computer display, the complete array of radio/RFD connections are not displayed in one snapshot, and prevention of operator errors is not built into the software control of the RFD. Therefore, radio assets that could be used for short term emergency diversions from the planned mission are often left unused because it takes too long to change the radio connections to and from the bands and modes needed to address the emergency.